Re: [CR] mixing spoke crosses

(Example: Framebuilders:Pino Morroni)

Date: Thu, 22 Mar 2001 18:44:20 -0500 (EST)
From: "Brandon Ives" <monkey37@bluemarble.net>
To: Joseph Bender-Zanoni <jfbender@umich.edu>
Cc: "Jon M. Schaer" <jschaer@columbus.rr.com>, DTSHIFTER@aol.com, bikevint@tiac.net, sterlingcapital@mail.com, classicrendezvous@bikelist.org
Subject: Re: [CR] mixing spoke crosses
In-Reply-To: <3.0.5.32.20010322181511.01695720@j.imap.itd.umich.edu>


Joe, I'll assume you mean you use less crosses on the NON-drive side. The non-drive side is usually lower tensioned when both of the crossings are the same. If you shorten the spokes on the non-drive side you increse the tension and equalize everything. Actually, equal tension is less important than equal dish. More important than both is a correctly built wheel. Again I don't want to debate anyones mode of building since if your wheels hold up it that's the correct way to build them. I build most of my wheels x3 drive, radial non-drive and have never had a problem.

enjoy, Brandon"monkeyman"Ives

"Nobody can do everything, but if everybody did something everything would get done." Gil Scott-Heron

On Thu, 22 Mar 2001, Joseph Bender-Zanoni wrote:
> I second everything discussed here and the rationale. I have used lower
> crosses on the drive side for years. I think that good rear wheels are best
> achieved by achieving the most uniform spoke tension between drive and
> non-drive side. Another way to achieve this is to have less spokes on the
> non-drive side as on my vintage Rovals.
>
> Joe
>
> At 04:45 PM 3/22/01 -0500, Jon M. Schaer wrote:
> >----- Original Message -----
> >From: <DTSHIFTER@aol.com>
> >To: <bikevint@tiac.net>; <sterlingcapital@mail.com>;
> ><classicrendezvous@bikelist.org>
> >Sent: Thursday, March 22, 2001 10:06 AM
> >Subject: Re: [CR] mixing spoke crosses
> >
> >
> >>
> >> The LH spokes of a (multi-speed) rear wheel do very little to effect
> >torque
> >> transmission, due to their inherently lower tension........
> >
> >The LH spokes in a standard wheel do transmit some torque to the rim, though
> >it is much less than the RH, but it has nothing to do with the lower tension
> >or shallower angle relative to the hub. As long as the spokes don't go
> >slack, either from vertical or tortional loading, they all transmit torque
> >the same (as a rigid column). The LH spokes transmit less torque because the
> >hubshell is absorbing the tortional load (actually twisting slightly).
> >Fatter rear hubshells (like Parallax) transmit torque better because of the
> >larger diameter.
> >
> >>
> >> Spring effect of the left has no "real world" relationship with stress and
> >> power transmission for the RH spokes. If it did, we would never see the
> >LH
> >> spokes of a rear wheel radially laced........
> >
> >I didn't see the original post, so I don't know what you mean by "spring
> >effect". But in regards to radially-laced RH spokes, I believe you should
> >look closely at the Mavic Ksyrium wheel. It is laced radially on the RH
> >spokes, and the idea has some merits. The radial spokes do actually transmit
> >some torque - they become very slightly non-radial - but a larger proportion
> >of the tortional load is caried by the LH spokes (this helps the overall
> >stability of the low spoke count wheel in accepting tortional load). Also,
> >the radial RH design (along with the particular spoke/hub interface of the
> >Ksyrium) helps minimize the differential tension (also helps the overall
> >stability of the low spoke count wheel).
> >
> >>
> >> Torque is more efficiently transferred with a 4x pattern (drive side) as
> >the
> >> lever arm (spoke) is 90o to the hub axis. 3x is also very good, and these
> >> days with materials being so much better that 20-30 years ago, there
> >really
> >> is no need for 4x (and 36o hubs!) wheels except tandems and fully laden
> >> touring bicyles.
> >>
> >
> >In principle, 4x does transmit the tortional load better because of the load
> >path of the spokes. But in practice, it's overkill on anything accept a very
> >low geared tandem. Even on loaded touring bikes or mtb's, no one person can
> >exert enough force on the pedals to significantly stress a well-built 3x
> >rear wheel.
> >
> >
> >> Your argument against fewer crosses on the LH side is not supported by the
> >> reference to 8-10 speed wheels...."...radial non-drive pattern on 8-10 sp
> >> wheels actually works pretty well." By "works pretty well" I am assuming
> >you
> >> mean "does not collapse"? I think I have addressed why they do not
> >collapse,
> >> but consider the following: We never see the RH spokes laced radially as
> >> they would have no wind-up under load (pedaling) and the fatigue factor
> >would be enormous.
> >>
> >
> >Again, look at the Mavic Ksyrium wheel. Similarly laced wheels could be
> >built from standard parts, as well. But the risk of flange failure from the
> >RH radial spokes isn't worth it, in my opinion. I do strongly recommend a 2x
> >RH, 3x LH pattern for most wheels I build for people, as a long-term use
> >wheel, and 1x RH, 2x LH pattern for the lighter riders or more limited use.
> >This is especially pertinent to Campy hubs because of the wide left center
> >dimension on their rear hubs. I only do the "race lace" 3x/radial for
> >limited use, and I explain thoroughly why it makes a bad wheel overall. It
> >does make the rear wheel stiffer laterally, but the differential tension is
> >WORSE, contrary to popular belief.
> >
> >>
> >> As I mentioned in my previous response to Sterling, I generally do 4x on
> >the
> >> RH (rear) whenever I am able to do so. Small flange hubs are not well
> >suited > for this, but it can be done with a little care. I do the LH
> >spoking (3x;
> >> 2x; 1x) in whatever I feel like and by what spokes I happen to have on
> >hand.
> >
> >That's actually backwards. Large flange hubs are less well suited to 4x
> >lacing. For a given spoke count and lacing pattern, the larger the flange
> >diameter, the closer to tangent the spoke leaves the flange. This causes the
> >spokes to overlap the head of the next spoke. But large flange hubs don't
> >need the higher cross lacings as much because the tortional load is lower.
> >This is why tandems still use (and benefit from) large flange hubs. On track
> >wheels, it's mostly just tradition.
> >
> >> I like to do 4x/2x as I like the pattern as viewed from the right-side to
> >the
> >> left-side of the wheel, and I think that 4x looks more "classical".
> >>
> >
> >Assuming the rim and spoke count are appropriately chosen, that pattern will
> >work. But from the mechanical standpoint, it's not optimum. There's just no
> >reason to have the RH 4x, and why risk the spoke head overlap? Lacing the
> >LH side fewer cross is only useful for a miniscule weight savings and
> >lateral stiffness gain, and possibly looks. But for the best combination of
> >durability and performance, it's the opposite of the best chioce.
> >
> >Jon Schaer